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BESSELI, BESSELJ functions return inaccurate result

demosfen 0 Reputation points
2025-03-10T08:12:20.1366667+00:00

BESSELI, BESSELJ functions return inaccurate result in compare to the results of other editors and libraries. For example results in excel:

=BESSELJ(1.9, 2) - 0.329925828669785

=BESSELI(1.5, 1) - 0.98166642847516605

But results in libreoffice, WolframAlpha and python scipy(https://docs.scipy.org/doc/scipy/reference/special.html) was different:

=BESSELJ(1.9, 2) - 0.329925727692387

=BESSELI(1.5, 1) - 0.9816664285779081

Why does the accuracy of the resulting differ and is this a bug or correct behaviour?

Excel Management
Excel Management
Excel: A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.Management: The act or process of organizing, handling, directing or controlling something.
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  1. Jiajing Hua-MFST 16,110 Reputation points Microsoft External Staff
    2025-03-11T02:42:13.7466667+00:00

    Hi @demosfen

    The differences in the results across different applications from the varying numerical methods and precisions. It’s not a bug, but a reflection of how each tool handles the computation.

    Similar thread: https://stackoverflow.com/questions/65592101/why-does-bessel-function-in-scipy-and-excel-give-different-results

    Thanks for your understanding.

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